Self-centering relay



l Feb. 3, 1959 s. K. BABcocK 2,872,546

sELF-CENTERING RELAY Filed Feb. 5, 1956 54 5e 5o ...L0

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STUAQT K. AccK ATTORNEY ilnited States Patent Oce SELF-CENTERING RELAY Stuart K. Babcock, Northridge, Calif. Application February 3, 1956, Serial No. 563,362 12 Claims. (Cl. 200-93) My present invention relates to magnetically operated electrical relays, and it relates particularly to a magnetically operated relay which has an inherently powerful selfcentering action, and which is therefore particularly adapted for neutral-olf operation.

The conventional magneticallyoperated electrical relay includes only afsingle complete magnetic path and has an armature which is inactive until polarized by an electrical actuating current. This single magnetic path provides such a relatively small amount of mechanical power that it is difiicult to obtain the required amount of sensitivity in the conventional relay.

Thus, using the conventional relay construction, it has heretofore been impossible to provide a very small relay which is highly sensitive. The only sensitive relays of conventional `construction are relatively large and expensive, and hence are undesirable for many present uses which require small, sensitive relays, such as present electronic computers.

Conventional, relatively large relays which are sensitive must be closely adjusted because of the inadequate mechanical power provided by the single magnetic path. The resulting limited amount of movement available and the inadequate power provided by the single magnetic path are insu'icient to close more than one contact at one time. However, it is often desirable to close two contacts at once.

The conventional relay is not inherently self-centering, and hence must be provided with -a suitable spring to become self-centering. Overcoming the spring tension in these conventional self-centering relays causes them to be even less sensitive than they would otherwise be. Such spring-actuated self-centering relays have very close tolerances and difficult adjustments, and are relatively large and expensive.

Since most electronic equipment operates through magnetically operated electrical relays, the above-described inadequacies in conventional prior art relays have seriously hampered the development and effectiveness of electronic equipment.

It is therefore an object of my present invention to provide a magnetically operated electrical relay which operates on a completely new principle of operation from conventional magnetically operated relays. This new principle of operation consists of establishing a balanced condition between adjacent magnets with like poles opposing and hence repelling one another, and then upsetting this balanced condition by applying an additional magnetism to a central region of at least one of the balanced magnets to increase the magnetic strength' at one pole of that magnet and decrease the magnetic strength of the other pole of that magnet.

My preferred embodiment consists of three parallel magnets with like poles at the same ends and with the center magnet being pivotal. The side magnets are magnetically associated, at their central regions, with electromagnets which may cooperate in operation to assist one another giving a maximum of mechanical power to 2,872,546 Patented Feb. 3, 1959 the central, pivoted magnet, or which may alternatively oppose one another in operation to provide a differential power output at the central, pivotal magnet.

Another object of my present invention is to provide a magnetically operated electrical relay which employs a plurality of separate magnetic paths, preferably four (4) in number, all of which operate cumulatively to produce mechanical power in the relay. v

Another object of my present invention is to provide a magnetically operated electrical relay having suicient mechanical power to permit a relatively small relay to be relatively sensitive.

Another object of my present invention is to provide a magnetically operated electrical relay having sulicient mechanical power to permit a relatively large amount of mechanical movement, whereby close adjustments are eliminated.

Another object of my present invention is to provide a magnetically operated electrical relay having sufhcient mechanical power and movement to permit a plurality of contacts to be closed at the same time.

Another object of my present invention is to provide a magnetically operated electrical relay which is inherently automatically self-centering without requiring a centering spring, and which is inherently always in perfect balance when in the centered position.

Another object of my present invention is to provide a magnetically operated electrical relay which is inherently highly sensitive, and which is therefore inherently un critical as to manufacturing tolerances, bearing accuracy and the like, rendering the relay very inexpensive to manufacture.

Another object of my present invention is to provide a magnetically operated electrical relay of the character described which, being inherently self-centering, is particularly adapted for neutral-off operation.

Another object of my invention is to provide a mag* netically operated electrical relay which may be so electrically connected as to mechanically reilect an electrical differential, thus providing a true differential relay.

Another object of my present invention is to provide a magnetically operated electrical relay which may be made both small and highly sensitive, and which may therefore be actuated by small, inexpensive transistors.

Other objects and advantages of my present invention will be apparent from the following description and claims, the novelty of my invention consisting in the features of construction, the combinations of parts, the novel relations of the members and the relative proportioning, disposition and operation thereof, all as is more completely described herein and as is more particularly pointed out in the appended claims.

In the accompanying drawings, forming a part of my present specication:

Figure l is a perspective view of my completely assembled relay with the armature in its normal, centered position.

Figure 2 is a vertical section along the line 2 2 in Figure l.

Figure 3 is a top plan view of my relay actuated so that the armature is rotated anti-clockwise.

Figure 4 is a top plan view of my relay similar to Figure 3 with the relay actuated so that the armature is rotated clockwise.

Figure 5 is a schematic diagram of my relay illustrating my completely new mode of operation.

My relay lil is provided with a flat base or yoke 12 upon which is mounted an upwardly directed boss 14 that is integrally attached to the center of base member l2 by a rivet 16 or by other conventional means.

A bearing hole 18 extends downwardly from the top of boss 14, terminating in a ilat bearing surface 20.

nemesis The armatureV 22 of my relay lil consists principally of a single permanent lmagnet 24 having an integral spindle 26 depending from its center. Spindle 26 is provided with a sharply pointed lower end 23, whereby armature 22 is pivotallyV mounted with spindle 2o disposed within bearing hole llS, andwith theV pointed lower end 28 of spindle 26V bearing againsty the flat bearing surface 20.

A pair'ofv electromagnets Sil and 32 are integrally connected to base member l2 near the respective ends of base member l2, and extendY upwardly from base member 12. Electromagnets 3l) and 32 include respective core members 34 and 36, and respective coil members 33 and 40 of conventional construction.

The upper ends of core members 34 and 36 are bent inwardly toward the pivotally mounted armature 2?., and permanent magnets 42 and are integrally attached to the upper ends of the respective core members 34 and 36. The upper ends of core members 34 and 36 are joined to the respective permanent magnets 42 and at substantially the magnetic and mechanical centers of the respective permanent magnets l2 and dal. rthe magnetic and mechanical centers are at the same point along the length of such a permanent magnet.

Permanent magnets 42 and 44 are disposed substantially parallel to one another, and are spaced apart sufficiently to permit a substantial amount of pivoting movement of armature magnet 2d. Permanent magnets 42 and 44 are substantiallyequidistant from armature magnet 24 on opposite sides of armature magnet 24, and all three of the magnets 24, 42 and 44 are disposed in substantially the same plane, which is a plane substantially perpendicular to boss 14 and armature spindle 26.

A contact point base member 46 is integrally attached to boss 14, and is composed of a suitable electrical insulator. in the drawings there are four (4) contact points, two (2) of the contact points, 48 and 59, being disposed on the same side of boss lll as electromagnet 3l), and the other two (2) Contact points, 52 and 545, being disposed on the same side of boss lo as electromagnet 32.

Contact points 4S, Sil, S2 and 5ft are disposed substantially below the permanent magnet 24 of armature 22 to permit a pair of Contact fingers 56 and 58 integral with armature magnet 24 and depending below armature magnet 24 to be disposed between the respective opposing pairs of contact points. Thus, one depending contact nger 56 extends downwardly to a position between the opposing Contact points 48 and 52, while the other depending contact linger 58 extends downwardly below armature magnet 24 to a position between the opposing Contact points l) and 54.

Depending contact fingers Se and 58 are preferably somewhat flexible and resilient, and although l haveA shown them as being substantially square in cross-section, it is to be understood that they may consist of conventional round wire members. Presently preferred contact fingers 56 and 58 consist of beryllium-copper wire which is rhodium plated.

A. presently preferred material of which the permanent magnets 24, 42 and 44 are composed, is well known in the trade as Alnico 4, although any other suitable permanent magnet material may be used. lt would also be possible to substitute electromagnets for the permanent magnets 24, l2 and 44, but this would have the disadvantages of unduly complicating the structure and of adding to the bulk of the structure.

A presently preferred sub-miniature embodiment of my invention which is highly sensitive utilizes electromagnet coil members 38 and 40 each having a resistance of substantially 1500 ohms resistance.

By the construction heretofore described and shown in the drawings, l am able to provide a sub-miniature relay that is highly sensitive and operable at approximately l milliampere at approximately 3 volts, thus requiring ln the embodiment of my invention illustratedV only approximately 3 milliwatts of power. Su"h a subminiature relay constructed in accordance with my present invention weighs less than one quarter of an ounce.

Referring now to Figure 5 of the drawings, I have there shown a schematic diagram of my present invention in which l have included a battery or other source of direct current all which is operatively connected to the electro-- magnet coil members 3SI and through a double pole, double throw switch 62. ln Figure 5 of the drawings l have arranged the electromagnet coil members and in series ngY relationship, `-/vhich is my preferred 'inding relationship for normal operation of the device, causing all four (4) of the magnetic paths to cooperate in operation to assist one another, getting the maximum mechanical power.

The three permanent magnets, 24, 42 and 44, are all disposed in parallel relationship in the unactuated condition of therrelay. By orienting magnets ft2, fi-l and il so that like poles re t the same ends of the magnets, both of the side magnets 52 and ld will repell center magnet 24 at both ends of center magnet 2d, causing center magnet2=l to become` self-cen ered in direct alignment with the side magnets @.72 and lf-r as shown in ure 5.

This self-centering action requires no springs, and is very powerful, with four (4) magnetic paths holding center magnet 2d against rotation.

Actuation of switch 62 to energize electromagnets and 32 to cause the end of electromac .t Sil that connects with permanent magnet to become a north pole, and to correspondingly cause the end of electromagnet 3?. that Connects with permanent magnet to become a south pole, will cause central magnet 24s to rotate anti-clockwise to the position shown in Figure 3. This rotation will be effected by the cumulative action of all four (4) of the magnetic paths. The north polarity of electromagnet will assist the north polarity at the upper end of permanent magnet 42. in Figure 5 to increase the repulsive force between the upper ends of magnets l2 and 24, causing an anti-clockwise Vforce to operate on center magnet 2d. Conversely, the north polarity of electromagnet Stb will diminish the south polarity of the lower end of magnet d2, thus greatly amplifying the anti-clockwise torque on center magnet provided by the repulsion of the north pole upper ends of magnets 42 and 25.-.

, The south polarity of electromagnet 32 increasesY tnc strength of the south pole, lower end of magnet dal, thus increasing the repulsion between the south pole low end of magnet 44 and the south pole lower end of p otalA magnet 24, thus further increasing the a wise torque on the center magnet 2d. Conversely, thc south pole of electromagnet 32 decreases the strength of the north pole at the upper end of magnet f creasing the repulsionbetween the upperer Ynets 44 and 25s,' further increasing the repuls Y the opposing south poles at the bottoms or" magna and 245, thus further increasing the anti-clockwise` tion on center magnet 24.

Since the repulsive eect of lille magnetic g creases according to the square of the distanceV1 the poles, it will be obvious that upon euergnng e tromagnets 39 and 32 in the aforesaid manner, pivotal magnet 24 will rotate anti-clockwise to a s able position short'of actual physical Contact between prrr-tal 24 and the stationary magnets l2 and 442. lelowev r. relatively small amount of electrical power is req in electromagnets 32 and 3% to cause a relatively lage mechanical displacement of thepivotal magnet 24, thus rendering this relay a highly sensitive one.

The above-described anti-clockwise rotation of pivotal magnet 24 will cause contact finger 56 to meet contact point 4%, and will cause Contact finger 53 to meet ecntact point 54, thus providing electrical communication between contact points 54 and 48,

It will be obvious from the above-described anticlockwise operation of pivotal magnet 24 that when switch 62 is reversed, causing electromagnet Sil to assume a south polarity adjacent to fixed magnet 42, and causing electromagnet 32 to assume a north polarity adjacent to fixed magnet 44, the reverse operation will be effected, causing pivotal magnet 24 to rotate clockwise to the position shown in Figure 4. This will cause contact nger 58 to engage contact point 5G, and will cause contact ringer 56 to engage contact point 52, thus providing electrical communication between Contact points 50 and 52.

Although I have shown electromagnets Sil and 32 as being wired in series in Figure 5, electromagnets 30 and 32 may alternatively be actuated independently of ane another to provide a true differential relay. in that case, both leads of each electromagnet, Sii and 32, are brought out, and one of the two electrical potentials to be com-- pared is applied across electromagnet 30, while the other electrical potential to be compared is applied across electromagnet 32, with these two potentials to be compared being applied to electromagnets A3&0 and 32 so as to produce opposing polarities rather than assisting polarities in electromagnets 30 and 32.

For example, if both potentials are in the same direction, such as positive, the same polarity will be assumed by both electromagnets 30 and 32 adjacent to their respective Xed magnets 42 and 44. When the two potentials are equal, the strength of electromagnets 30 and 32 will be equal, whereby pivotal magnet 24 will remain absolutely centered. When one potential becomes larger than the other, the pivotal magnet 24 will rotate in a corresponding direction an amount corresponding to the difference in potential, and when the potentials are reversed the pivotal magnet 24 will reverse in direction.

Although I have shown and described my present invention with four (4) contact points, 48, 50, 52 and 54, and with two (2)` cooperating contact lingers Se and 58 depending from the armature magnet 24, it will be obvious that any switching combination can be provided in my relay. For example, my relay may be provided as a single pole, single or double throw switch, or may be provided as a double pole, single or double throw switch.

A presently preferred form of single pole, double throw switch utilizes a pair of depending contact lingers 56 and S8, with only a single pair of contact points 48 and Si) on one side of the armature 22. In this arrangement, a ne, eXible conducting wire is integrally connected to spindle 26 to provide current to the contact iingers 56 and 58.

My new structure consisting of a plurality ot aligned magnets with like poles at the same ends, and with one of the magnets being pivoted, and with electromagnets -being applied to the centers of the un-pivoted magnets,

results in a new mode of operation and new and beneficial results which are so surprising that they completely overcome most of the diiiiculties intrinsic in conventional prior art relays.

Thus, my new relay has a strong self-centering action, and is therefore particularly adapted for neutral-off operation, without requiring any springs whatsoever.

The plurality of separate magnetic paths, preferably four (4), provide greatly increased mechanical power' over conventional prior art relays. This provides a high degree of sensitivity, and permits my relays to be constructed very small, while still retaining high sensitivity. This also eliminates close tolerance problems, simplifying manufacturing procedures.

The large amounts of mechanical movement available in my present invention, coupled with the increased power, eliminate the necessity for diilicult and close adjustments, and permit a plurality of contacts to be closed simultaneously.

My present invention has the additional inherent advantage that it is particularly adaptable as a true differential relay to compare two separate electrical potentials.

The simplicity and completely uncritical nature of my present relay make it far more dependable than conventional prior art relays, and of course, the strong selfcentering action and great mechanical power inherent in my relay are important factors in this reliability.

The small power requirements of my present relay make it particularly adaptable for use in connection with transistors.

It is to be understood that the form yof my invention herein shown and described is my preferred embodiment and that various changes in the shape, size and arrange- 4 ment of parts may be resorted to without departing from the spirit of my invention, or the scope of my appended claims.

i claim:

l. An electric current responsive device including a pivoted permanent magnet pivoted at a point intermediate its two poles, a stationary permanent magnet disposed adjacent to said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, and an electromagnet having one pole magnetically connected with said stationary magnet intermediate its two poles.

2. An electric current responsive device including a pivoted permanent magnet pivoted at a point intermediate its two poles, a pair of stationary permanent magnets disposed on opposite sides of said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, and an electromagnet pole magnetically connected with each of said stationary magnets intermediate its two poles.

3. An electric current responsive device including a pivoted permanent magnet pivoted at a point intermediate its two poles, a pair of stationary permanent magnets disposed on opposite sides of said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, and an electromagnet pole of one polarity magnetically connected to one of said stationary magnets intermediate its two poles and an electromagnet pole of the opposite polarity magnetically connected to the other of said stationary magnets intermediate its two poles.

4. A magnetic force actuated device including a pivoted permanent magnet pivoted at a point intermediate its two poles, a pair of stationary permanent magnets disposed on opposite sides of said pivoted magnet, like poies of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, and selective means for substantially simultaneously applying a magnetic force of one polarity to one of said stationary magnets intermediate of its two poles and a magnetic force of the opposite polarity to the other of said stationary magnets intermediate of its two poles.

5. A magnetic force responsive device including a pivoted permanent bar magnet pivoted at a point intermediate its two poles, a pair of substantially parallel stationary permanent bar magnets disposed in substantially the same plane as said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, the pivoting axis of said pivoted magnet being substantially perpendicular to said plane, and selective means for substantially simultaneously applying a magnetic force of one polarity to one of said stationary magnets intermediate its two poles and a magnetic force of the opposite polarity to the other of said stationary magnets intermediate of its two poles.

6. An electric current actuated relay including a pivoted permanent magnet pivoted at a point intermediate its two poles, a stationary permanent magnet disposed adjacent to said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation, an electromagnet having one pole magnetically connected with one of said pivoted 27 and stationary magnets intermediate its two poles, astationary electrical contact member, and a movable electrical contact member loperatively connected to said pivoted, magnet and selectively operatively engageable with saidv stationary Contact member according to the pivotal positionV of saidl pivotal magnet.

7. An electric current actuated relay including a pivotedpermanent magnet pivotedat a pointintermediate its two poles, a stationary permanent magnet disposed adjacent to said pivoted magnet, like poles of said pivoted and stationary magnets being disposed e. 1' to each other in' repelling relation, an electromagrA ing one pole magnetically connected with said stationary magnet intermediate its two poles a stationary electrical contact member, and a movable electrical contact member operatively connected to said movable m i selectively operatively engageable with said sta contact member according to the pivotal position of said pivotal magnet.

8. An electric current actuated relay including a pivoted permanent magnet pivoted at a point intermediate its two poles, a pair of stationary permanent magnets disposed on opposite sides of said pivoted magnet, like poles of said pivoted and stationary magnets being dis-- posed adjacent to each other in repelling relation, an electromagnet pole magnetically connected with each of said stationary magnets intermediate its two poles, a stationary electrical contact member, and a movable electrical Contact member operatively connected to said pivoted magnet and selectively operatively engageable with said stationary contact member according to the pivotal position of said pivoted magnet.

9. An electric current `actuated relay including al pivoted permanent bar magnet pivoted at a point intermediate its two poles, a pair of substantially parallel stationary permanent bar magnets disposed in sub-stam tially the same plane as said pivoted magnet, like poles of said pivoted and stationary magnets being disposed adjacent lto each other in repelling relation, the pivoting axis of said pivoted magnet being substantially perpendicular to said plane, an electromagnet pole magnetically connected with each of said stationary magnets intermediate its two poles, a stationary electrical contact member, and a movable electrical contact member operatively connected to said pivoted magnet and selectively operatively connectable with said stationary contact member according to the pivotal position of said pivoted magnet.

10. An electric current actuated relay including a pivoted permanent magnet pivoted at a point intermediate its two poles, a pair of stationary permanent magnets disposed on opposite sides of said pivoted magnet, like poles of said pivoted Vand stationary magnets being disposed adjacent to each other in repelling relation whereby said pivoted magnet will be self-centered, an electromagnet pole of one polarity magnetically connected to one of said stationary magnets intermediate its two poles and an electromagnet pole of the opposite polarity magnetically connected to the other of said stationary magnets intermediate its two poles, a stationary electrical contact member, and a movable electrical contact member operatively connected to said pivoted mag-V net, said movable contact member being selectively operatively connectable with said stationary contact member according to the pivotal position of said pivoted magnet. v

11. An electric current actuated relay including a pivoted permanent bar magnet pivoted at a point intermediate its two poles, a pair of substantially parallel stationary permanent bar magnets disposed in substan tially the same plane as said pivoted magnet on opposite sides of said pivoted magnet, the pivoting axis of said pivoted magnet being substantially perpendicular to said plane, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation whereby said pivoted magnet Will be self-centered, an electromagnet pole magnetically connected` with each of said stationary magnets intermediate its two poles, a

" electrical Contact member, and a movable electrical contact member operatively connected to said pivoted magnet, said movable contact member being selectively operatively connectable with said stationary contact member according to the pivotal position of said pivoted magnet.

l2. An electric current actuated relay including a pivoted permanent bar magnet pivoted at a point intermediate its two poles, a pair of substantially parallel stationary permanent bar magnets disposed in substantially the same plane as said pivoted magnet on opposite sides of said pivoted magnet, the pivoting axis of said pivoted magnet being substantially perpendicular to said plane, like poles of said pivoted and stationary magnets being disposed adjacent to each other in repelling relation whereby said pivoted magnet will be self-centered, an electromagnet pole of one polarity magnetically connected to one of said stationary magnets intermediate its two poles and an electromagnet pole of the opposite polarity magnetically connected to the other of said stationary magnets intermediate its two poles, a stationary electrical Contact member, and a movable electrical contact member operatively connected to said pivoted magnet, said movable contact member being selectively operatively connectable with said stationary contact member according to the pivotal position of said pivoted magnet.

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